Gitignore jinja2 and markupsafe

Change-Id: I9c05ddc2ca2e3377cc8a9d13c3e4faa2f17a49a5
Reviewed-on: https://pdfium-review.googlesource.com/3930
Reviewed-by: Nicolás Peña <npm@chromium.org>
Commit-Queue: Nicolás Peña <npm@chromium.org>
diff --git a/.gitignore b/.gitignore
index 289162c..2c3fd5a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,9 +10,11 @@
 /third_party/freetype/src
 /third_party/icu
 /third_party/instrumented_libraries
+/third_party/jinja2
 /third_party/libjpeg_turbo
 /third_party/llvm
 /third_party/llvm-build
+/third_party/markupsafe
 /third_party/skia
 /third_party/yasm/binaries
 /third_party/yasm/source/patched-yasm